Production of metal articles by extrusion



Feb. 28, 1961 A. B. GRAHAM PRODUCTION OF METAL ARTICLES BY EXTRUSION Filed Jan. 24, 1958 ALE/VAN DE)? 34 wow GMHA M Attorney United States Patent C) a to The International Nickel Company, Inc., New York. N.Y.', a corporation of Delaware Filed Jan. 24, 1958, Ser. No.'71'1,100 Claims priority, application reat Britain Jan. 22;, 1957 a crane, remov -17 The present invention relates to extrusion and, more particularly to an extrusion die of special configuration for use in an extrusion operation for the production of a plurality of high temperature alloy elongated mem bers simultaneously and to a method for accomplishing the same.

As is well known to those skilled in the art, high melting point base-metals and base-metal alloys having melting points upwards of 900 C. are difliculty extru'dable. Included among such high base-metals and base-metal alloys are nickel, cobalt, iron and alloys thereof including nickel-chromium alloys, nickel-chromium-iron alloys, nickel-chromium-cobalt alloys, nickel-copper alloys, ironchromium alloys, cobalt-chromium alloys, steels, stainless steels, etc. Substantial amounts of one ormore other alloying elements such as tungsten, aluminum, titanium, columbium, zirconium, molybdenum, etc., are often found in these alloys, particularly those containing nickel and chromium. The high melting points of such metals and alloys require the utilization of rather high extruding pressures at high temperatures and, as a result, a substantial amount of heat is transmitted to the dies which, among other factors, adversely affects the dies and necessitates frequent replacement thereof. It is further known, that high melting point base-metals and base-metal alloys such as those enumerated above can be formed into rod or wire by the extrusion of a billet of the metal through a die if there is adequate lubrication of the metal as it passes through the the. Glass is a suitable lubricant for this purpose, and glass fiber is usually put in the outlet end of the extrusion press, the glass melting when in contact with the billet and flowing with the billet through the die.

Now it is highly desirable commercially to produce a plurality of high melting point base-metal and basemetal alloy elongated members or sections, e.g., rods or wires, simultaneously from a single billet. However, in attempting to so do by providing the extrusion press with an end wall or die containing several die orifices, considerable difiiculty is encountered. In particular, it has been found that even when a glass lubricant is employed, the glass lubricant ceases to flow uniformly to all the orifices, and some of the surfaces of the extruded billet metal are rough and uneven as a result of a lack of adequate lubrication. Thus, further tedious and expensive operations are required to obviate the defects of the extruded pieces. Although attempts were made to overcome the foregoing difiiculties and other difliculties, none, as far as I am aware, was entirely successful when carried into practice commercially on an industrial scale.

It has now been discovered that a plurality of high melting point base-metal and base-metal alloy elongated members or sections having relatively smooth surfaces and being devoid of deleterious surface defects can be produced simultaneously through the utilizationof a die of special structural arrangement.

It is an object of the present invention to provide a face defects.

Patented Feb. 28, 1961 2 die of special configuration adapted for use in an extrusion operation to produce a plurality of high melting point base-metal and base-metal alloy elongated members, e.g., rods or wires, simultaneously.

Another object of the invention is to provide by extrusion a plurality of high melting point base-metal and base-metal alloy rods, wires, etc., simultaneously which are characterized by relatively smooth surfaces and are devoid of detrimental surface defects.

The invention also contemplates providing a process for extruding aplurality of high melting point base-metal and base-metal alloy rods, wires, etc, simultaneously wherein adequate lubrication of each extruded rod or wire :is obtained, whereby the incurrence bf detrimental surface defects is substantially eliminated.

It is a further object of the invention to provide a die having a special structural arrangement which facilitates and insures adequate lubrication for 'each of a plurality of high melting point base-metal and base-metal alloy elongated sections simultaneously extruded, thus providing sections having relatively smooth surfaces.

Other objects and advantages will become apparent from the following description taken in conjunction with the accompanying drawing in which:

Fig. 1 is a plan view of part of an extrusion press illustrating the novel die contemplated by the present invention; and

Fig. 2 depicts a sectional view taken on section I I--II ously a pluralityof high v-meltin'gpoint i.'e., upwards or 900 C., base-metal and base-metal alloy elongated mem-' bers or sections characterized by relatively smooth extruded surfaces and by being devoid of detrimental sin- The "die (which can also be formed as the end wall of an extrusion press) is comprised of a are face having a concave contour or configuration and contains a plurality of pockets or cavities each of which is adapted to receive a glass-like or glassy lubricant which can take the form of -a pad or plate orother suitable form. Each of the pockets or cavities contains a die orifice for receiving billet metal to be extruded. Thus, in accordance with the invention, lubrication is provided for each member or section, e.g., rod, wire, etc,

to be extruded and the lubricant is forced, when melted, to flow to the die orifice through which the rod or Wire is to be formed.

In carrying the invention into practice, it is highly advantageous in achieving optimum results in accordance with the invention, to provide a centrally located cavity in the die face and disposing the pockets thereabout, preferably in concentric spaced relation thereto. The centrally located cavity encourages metal in the center of the billet to flow more easily and the shape should be such as to enhance the flow lines. It is further advantageous that the base of each of the pockets or cavities leading from the die orifices be inclined to the center line or central longitudinal axis of the die or extrusion press so that the extruded refractory high temperature alloy sections emerge at an inclination. This feature of an inclined outlet passage is of importance to eliminate dead metal zones and keep the line of extrusion normal to the local die face. A guide passage registering with the outlet passage and substantially parallel to the center line or longitudinal axis of the die or extrusion press can be employed such that the extruded members or sections move onwards parallel to the center line. A further die orifice can advantageously and suitably be provided in the centrally located cavity so that an extruded refractory section emerges along the center line.

For the purpose of giving those skilled in the art a better understanding of the invention and/or a better appreciation of the advantages of the invention, reference is now made to the drawing which illustrates, by way of example, apreferred embodiment 'of'the extrusion die contemplated in accordance with the invention.

Referring to Figsrl and 2, there is illustrated a cylindrical container 1 with a flaring end which receives a complementary die 2 held in position by holder 3. The die is of generally concave contour and has four pockets 4 evenly spaced around a central'cavity 5. There is a die orifice 6 in the base-of each pocket, and a passage 7 leading from each orifice in the outlet face of the die and there registering witha guide'passage 9 in the holder 3. The shape of a rod during extrusion is indicated by dotted lines 8. Recess 11 in centrally located cavity as shown in Figs. 1 and 2 may advantageously open into another die orifice and passage as shown in phantom at 12in Fig. 2. t

It is to be noted that the present invention is not to be confused with the well known bridge piece dies wherein a mixing chamber is employed and the dies usually serve as a fixing block for the use of long and short mandrels.

As will be readily apparent to those skilled in the art, the term elongated members or sections as used herein include the usual metallurgical products in the form of rods, wires, tubes, bars, sheet, strip, etc.

Although the present inventionhas been described in conjunction with preferred embodiments, it is to be understood that modifications and variations may be resorted to without departing from the spirit and scope of the invention, as those skilled in the art will readily understand. Such modifications and variations are considered to be within the purview and scope of the invention and appended claims. a

- I claim:

1. An extrusion die for the simultaneous extrusion of a plurality of solid metal articles, said die comprising-a single piece structure having a generally concave billet engaging face, the latter having a central frusto-conical cavity with outer frusto-conical cavities thereabout, said central cavity having its axis coincident with the die axis and having a bottom which is substantially perpendicular- 4 outer cavities having a bottom which is substantially perpendicular to its corresponding said cavity axis, each of said central cavity and said outer cavities having a contrally disposed extrusion orifice which leads into a clearance passage, said orifice andfsaid passage being coaxial with theirrespective. preceding cavity each of-said central cavity and saidouter cavities having'itsupper edge rounded and having a fillet" provided between its lower edge and the corresponding cavity bottom, whereby workmetal will tend to W substantially uniformly tothe respective said centralcavity and said outer cavities and each cavity will serve as a reservoir for lubricant which is introduced before said workmetal. g

2. Anextrusion die for the simultaneous extrusion of a plurality of solid metal articles, said die comprising a single piece structure having a generally concave billet engaging face, the latter; having frusto-conical cavities uniformly disposed about the die] axis, each of said cavities extending in a direction which is o'utwardly'inclined thus making each cavity axis closer to said die axis on the billet engaging side than on the exit side of said die, each of said cavities having a bottom which is substantially perpendicular to its corresponding said cavity axis, said bottom being the smaller base of its corresponding cavity, each of said cavities having a centrally disposed extrusion orifice which leads into a clearance passage, said orifice and said passage being coaxial with their respective preceding cavity, each of said cavities having its upper edge rounded and having a fillet provided between its lower edge and the corresponding cavity bottom, whereby workmetal will tend to flow substantially uniformly to the respective said cavities and each cavity will serve as a reservoir for lubricant is introduced before said workmetal.

- References Cited in the tile of this patent UNITED STATES PATENTS 2,168,641, Arbogast Aug. 8, 2,178,529 Calkins et al. Oct. 31, 1939 2,341,749 Webb Feb. 15, 1944 2,638,213 Clark May 12, 1953 2,706,850 Sejournet et al. Apr. 26,v 1955 7 FOREIGN PATENTS 437,075 Great Britain Oct. 23, 1935- 607,285 Great Britain Aug. 27, 1948, 717,358 Germany Feb. 12, 1942. 1,130,017 France Sept. 17, 1956 which 

